Re: how dodgy are these examples of char array use

From:

"Jim Langston" <tazmaster@rocketmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 23 May 2006 03:04:24 -0700

Message-ID:

<P6Bcg.668$my.170@fe04.lga>

"voidtwerp" <voidtwerp@gmail.com> wrote in message
news:1148377618.436559.241610@38g2000cwa.googlegroups.com...

Hi,

showing my extreme ignorance I would like comments how the char arrays
are used here, ie are these valid or dangerous uses (the reason I ask
is because constructs like these occur in some code I am looking at).

#include <iostream>
#include <stdlib.h>

using namespace std;

class C
{
   public:
   C();
   void f1();
   private:
   char* f2();
   void f3();
};

C::C(){}
void C::f1()
{
   char * p;
   int i=3;
   while(i--)
   {
       try
       {
               switch (i)
               {
               case 2:
                  p="is this dodgy?";

p is pointing to a constant character array. As long as you don't try to
change it or delete it, it should be okay.

                  throw 1;
                  break;
               case 1:
                  p=f2();

Same thing here, it's just pointing to a constant character array defined in
f2()

                  throw 2;
                  break;
               case 0:
                  f3();

This really doesn't do anything. p never gets changed since f3 assigns a
local varaible then throws.

                  break;
               default:
                  cout << "ERK!" << endl;
               }
       }
       catch(char * v)
       {
               cout << v << endl;
       }
       catch(int e)
       {
               cout << p << endl;
       }
       catch(...)
       {
               cout << "ERK2!!" << endl;
       }
   }
}

char* C::f2()
{
   char * v = "how dodgy is this?";
   return v;
}

void C::f3()
{
   char *v="is this any better/worse?";
   throw v;
}

int main(int argc, char *argv[])
{
C c;
c.f1();
system("PAUSE");
return 0;
}